Telephone spring-jack



(No Model.)

M mg Ire raras WILLIAM o. MEIssNnR, or cIIIci-ieo,

ILLINOIS, ASSIGNOR TO THE AMERI- TELEPHONE SPRING-JACK.

SPECIFICATION forming' part of Letters Patent No. 579,239, dated March23, 1897. Application led January 17, 1896- Serial No. 575,919. (Nomodel.)

.To all whom t may concern.-

Be it known that I, WILLIAM O. MmssNnr., a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Telephone Spring-Jacks,of which the following is a speciiication.

My invention relates to telephone springjacks, and has for its object toprovide a new and improved spring-jack, of which the following is adescription, reference being had to the accompanying drawings, wherein-Figure l is a longitudinal section through a sprin g-j ack embodying myinvention. Fig. 2 is a view of the same with the parts differentlydisposed. Fig. 3 is a diagram of a telephone system having twosubscribers and provided with Inyimproved spring-j ack. Fig. a shows amodified form of spring-jack to be usedupon a system that has no groundreturn.

Like letters refer to like parts throughout the several figures.

As illustrated in the drawings, my device consists of the plate A, ofinsulating material, having the different parts associated therewith. Atone end of the plate A is an upwardly-projecting piece A', also ofinsulating material, and provided with an opening through which isinserted the pin B. Said pin is made of insulating material and has itsouter end B beveled. or cone-shaped, as shown. Extending through the pinB is a metallic rod B2, which projects beyond the beveled end of thepin, as shown. Ahandle B2 is connected with the pin B and is providedwith a conductor B4, which is electrically connected with the rod B2. Astationary contact A2 is connected with the plate A and is so positionedthat it is engaged by the pin B when said pin is inserted through thehole in the part A. This contact may be of any suitable description and,as shown, consists of a hollow tube through which the pin is adapted tobe inserted. The contact A2 is electrically connected with the conductorA2,which is connected by wire A4 to one terminal of the circuit.

Connected with the plate A is a spring-contact C, provided with theprojecting part C', adapted to engage the rod B2, said springcontactbeing connected with the circuit by means of the wire C2. The projectingpart C maybe made in any suitable manner. As herein shown it is made bybending the springcontact downwardly, so as to form a V-shapedprojection. The free end of the spring-contact C is interposed betweenthe stationary contacts A2 and C3, the contact C2 adapted to beconnected in circuit by the wire C4.

The outer end of the pin B is beveled, as shown, as is also theprojection C', the beveled surfaces on the projection and pin engagingeach other when the pin is in position. The handle B2 is so shaped as toengage the part A', so as to limit the inward motion of the pin B, andthe parts are so positioned thatwhen the end of the pin is in contactwiththe projection C' on the spring-contact C the pin may still be moveda short distance inwardly before being stopped by the engagement of saidhandle with the upwardly-projecting part A'.

Vhen the pin B is removed from its socket, the spring-contact C isincontact with the stationary contact A2. When the pin is inserted and isin the position shown in Fig. l, said spring-contact is moved out ofcontact with the contact A2 and in contact with the rod B2 in the end ofthe pin B. If, now, the pin is moved inwardly to the position shown inFig. 2, the beveled end of the pin B engaging the beveled surfaces ofthe projection C moves the spring-contact C to the position shown inFig. 2, Where it is in contact with the stationary contact C3.

As the pin Bis of insulating material there will be no contact with thecircuit leading from said pin. When the pin is moved to the positionshown in Fig. 2 and then released, it is automatically moved back to theposition shown in Fig. l on account of the engagement of the beveledsurfaces on the projection C and the pin B.

I have shown diagrammatically in Fig. 2 a telephone system of twosubscribers containing myspring-jack or circuit-changing device. Theinstrument C5 of one subscriberis connected to the ground at C and tothe spring-contact C, said contact being normally connected with thestationary contact A2, which is connected through the annunciator C7with the ground at CS. The stationary IOO contact C2 is connected bywire C4 with the generator E,which generates the current used insignaling. The conducting part B2 of the pin B is connected by wire B4with a second pin B9, and is also connected with the contact B5,operated by the key B6, and opposed to the contact B7, connected withthe opcrators instrument B2. The instrument F of the second subscriberis connected up in a manner similar to that of the instrument C5 of thefirst subscriber. When the parts are in the position shown in Fig. 3 andthe subscriber having the instrument C5 calls up, the circuit will be asfollows: from ground C6 through the instrument C5 and wire C2 to contactC, thence through contact A2, wire A4, annunciator C7 to ground C8. Theannunciator shows the central operator that the subscriber is calling,and the pin B is inserted in the contact A2, the parts taking theposition shown in Fig. 1. The key B6 is then depressed, bringing thecontact B5 into contact with contact B7. This places the operatorsinstrument B8 in circuit with the subscribers instrument C5, so that thenumber wanted may be made known to the operator. The pin B9 is theninserted into the stationary contact A2, associated with the instrumentF in this case, and is moved to the position shown in Fig. 2, so as toconnect the spring-contact C with the stationary contact C3. The circuitwill then be as follows: from generator E to contact G3, associated withthe instrument F, thence through spring-contact C, thence by wire C2through the signaling device of the instrument F, thence to the groundC6, and thence back to the generator. The signal of the subscriberhaving the instrument F will then be operated. IVhen the pin B9 isreleased, it is automatically moved to the position shown in Fig. l andthe two instruments F and C5 are in circuit, so that the two subscribersmay communicate with each other.

I have only shown a system with two subscribers, as such a system willillustrate my invention, but it is of course evident that it may beapplied to a system containing any number of subscribers. I have alsoonly shown a grounded system, but my invention is applicable to a systemhaving a metallic circuit. In this event the spring-contact C isconnected to one branch of the talkingcircuit and the stationary contactA2 with the other branch.

I have illustrated in Fig. et a circuit-changing device as modified foruse with a metallic circuit. The operation of this device is similar tothe operation of the circuit-changer when used on a grounded system, theonly difference being that there must be two circuit connections insteadof one. I obtain this by connecting a conducting-piece G to the pin B,so as to make contact with the stationary contact A2, saidconducting-piece being connected by wire with a similar conductingpieceon a second pin. A spring or movable contact G is associated with thestationary contact A2 and is adapted to be brought into contacttherewith by engagement with the handle B3 when the pin B is moved toits eX- treme forward limit. It will be seen that by this constructionthe signaling device of any subscriber is easily and quickly operatedwithout operating the signaling device of the other subscriber orwithout in any way affecting his instruments, said latter subscriberbeing entirely disconnected from the generator supplying thesignaling-current. I have described these several parts in detail, butit is evident that they may be greatly changed in form, construction,and arrangement without departing from the spirit of my invention, and Itherefore do not wish to be limited to the construction shown.

I claiml. A circuit-changing device comprising a spring-contactinterposed between two stationary contacts and normally in contact withone of said contacts, a contact-pin composed in part of conductingmaterial, said pin adapted when interposed between said springcontactand one of said stationary contacts to separate said contacts andconnect the springcontact with the conducting part of the pin, said pinso constructed that when moved to a predetermined position saidspring-contact is moved out of contact with the conducting part thereofand into contact with said second stationary Contact.

2. A circuit-changing device comprising a spring-contact interposedbetween two stationary contac ts and normally in contact with one ofsaid contacts, a contact-pin composed in part of conducting material,said pin adapted when interposed between said springcontact and one ofsaid stationary contacts to separate said contacts and connect thespring-contact with the conducting part of the pin, said pin soconstructed that when moved to a predetermined position saidspring-contact is moved out of contact with the conducting part thereofand into contact with said second stationary contact, the opposedcontact-surfaces onsaid pin and spring-contact so shaped that said pinis automatically moved when released so as to be electrically connectedwith said spring-contact.

3. A circuit-changing device comprising a spring-contact interposedbetween two stationary contacts and normally in contact with one of saidcontacts, a pin of insulating material having a conductor projectingfrom the end thereof and adapted when inserted between saidspring-contact and one of said stationary contacts to engage saidspring-contact and move it out of contact with its opposed contact, saidinsulating-pin provided with an inclined surface adapted to be broughtinto engagement with an inclined surface on said spring-contact by afurther movement of said pin so as to move said spring-contact an ddisconnect it from the conductor projecting from the pin, at the sametime connecting it with said second stationary contact, and a IOO IIO

device for limiting,` the further movement of said pin so that whenreleased it is automatically moved so as to disconnect thespringcontact, and a second station ary contact, connectiug said springcontact with the conductor projecting' from the end of the pin.

4. A circuit-changing device comprising a spring-contact interposedbetweenl two stationary contacts, an insulating-pin provided at one endwith a device adapted to limit its inward movement, and at the other endwith a conductorl adapted to engage said springcontact when the pin isin a predetermined position, said insulating-pin provided with aninclined surface opposed to a V-shaped projection on the spring-contactso as to engage the same when said pin is moved to the limit of itsinward movement, substantially as described.

5. A Circuitbhanging device for telephoneexchanges comprising a seriesof stationary contacts connected with the signaling-generator, a secondseries of stationary contacts, each connected with one branch of thetalking-circuit of a subscriber, a series of springcontacts eachconnected with the other branch of said talking-circuits, one to eachbranch, and interposed between said talking-circuit contacts and saidgenerator-circuit contact, said spring-contacts normally in contact withone set of the opposed stationary contacts, a series of insulating-pinsprovided at one end with projecting conductors electrically counectedtogether in pairs and adapted when inserted between said spring-contactsand their opposed stationary contacts to disconnect the spring-contactsfrom the opposed stationary contacts and connect them with theconducting part of the pins whereby any two subscribers can be connectedtogether, said pins and spring-contacts so constructed that when eitherof said pins is given a further movement, the signal of the associatedsubscriber is operated, said pin returning,` to its normal position whenreleased.

VILLIAM O. MEISSNER.

Witnesses:

DONALD M. CARTER, FRANCIS M. IRELAND.

